Reactive (or regular) Spring Data Neo4j keeps around relationships - neo4j

Question

I am trying to assign/save a new list with a single node and expecting it to be in the same state after the save.
Yet, if I return the Foo from Neo4j and reassign the list of Bars, it maintains a list of all Bars that were previously added.
I would expect that previous Bar nodes in Neo4j are orphaned and the Foo only has a single relationship at any given time.
How can I tell Spring Data for Neo4j to not "merge" (or whatever you call it) the list and reset the relationships exactly as the list is passed in (with one node).
Any thoughts, advice, or guidance would be greatly appreciated! Thanks!
Below, you can find a straightforward application that reproduces this problem.
#Component
public class RelationshipCommandLineListener implements CommandLineRunner {
#Autowired
private FooRepository fooRepository;
#Override
public void run(String... args) throws Exception {
fooRepository.findById("foo").defaultIfEmpty(new Foo("foo", Collections.emptyList()))
.map(foo -> {
foo.setBars(List.of(new Bar(System.currentTimeMillis())));
return foo;
})
.flatMap(foo -> fooRepository.save(foo))
.block();
}
}
#SpringBootApplication
public class Main {
#Bean(ReactiveNeo4jRepositoryConfigurationExtension.DEFAULT_TRANSACTION_MANAGER_BEAN_NAME)
public ReactiveTransactionManager reactiveTransactionManager(Driver driver, ReactiveDatabaseSelectionProvider databaseNameProvider) {
return new ReactiveNeo4jTransactionManager(driver, databaseNameProvider);
}
public static void main(String[] args) {
new SpringApplicationBuilder()
.web(WebApplicationType.NONE)
.sources(Main.class)
.build()
.run(args);
}
}
Foo, simple holds up to a list of Bars.
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#Node(primaryLabel = "Foo")
public class Foo {
#Id
String id;
private List<Bar> bars = new ArrayList<>();
}
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#Node(primaryLabel = "Bar")
public class Bar {
#Id
String id;
}

Answer 1

You need to define a relationship in your model Foo. Try this:
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#Node(primaryLabel = "Foo")
public class Foo {
#Id
String id;
#Relationship(type = "HAS_BARS", direction = OUTGOING)
private List<Bar> bars = new ArrayList<>();
}